The worst crash (in terms of fatalities) to happen in the state of Oklahoma was on 22 April 1966. The Electra was flying a charter for the Army when it crashed on approach to the Ardmore Municipal Airport (the former Ardmore AFB). Of the 93 passengers and five crew, only 15 passengers survived. It was determined the Captain (also the president of the airline) suffered a heart attack and slumped over the controls. The co-pilot didn't have time or altitude to recover the airplane before impact.